Assalaamu ‘Alaykum, I have a big problem. A long time ago, the wife of my paternal uncle made a copy of the key of my grandfather's closet. From time to time, she started to take money from that closet without telling anyone. She began to give a part of it to my mother so that she may keep silent and not to tell anyone. My mother took a part of the money because my grandfather used to deprive them of everything and bought a bracelet. Is that money unlawful? How?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

What the wife of your paternal uncle and your mother are doing—taking the money of your grandfather—without telling him is a theft and manifest sin. Allaah Almighty says (what means): {And do not consume one another's wealth unjustly.} [Quran 2: 188]

The Prophet, sallallaahu ‘alayhi wa sallam, said: “Your blood and your wealth and your honor are inviolable.” [Al-Bukhari and Muslim]

It is incumbent upon both of them to repent to Allaah Almighty from that awful sin and seek His forgiveness. Also, they have to return the money that they have taken without just cause. The Prophet, sallallaahu ‘alayhi wa sallam, said: “It is not permissible [to take] the property of a Muslim except with his consent.” [Ahmad] 

Allaah Knows best.